Method for jump starting a vehicle

ABSTRACT

A method for jump starting a vehicle comprising causing a control unit to set a reference voltage by choosing a point from a chart plotting voltage across a starting battery versus time during a vehicle start; determining whether the voltage across a starting battery of the vehicle is less than the reference voltage; closing a switch if the determination is positive, thereby causing an external power source to supply high current to the starting battery; adding the high current and current from the starting battery to obtain a total current; and supplying the total current to a starter motor of the vehicle so as to start the vehicle. An apparatus for thus jump starting a vehicle is also disclosed.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a method for jump starting a vehicle disabledby a depleted starting battery by connecting an external power source tothe disabled vehicle's battery to quickly supply sufficient current tothe vehicle's battery which in turn supplies required power to a startermotor for starting the disabled vehicle.

2. Description of Related Art

It is typical to jump start a vehicle disabled due to a dead battery.Jump starting is a method of starting a vehicle powered by an internalcombustion engine when the vehicle's battery has been discharged. Asecond battery (often in another vehicle) is temporarily connected toprovide starting power to the disabled vehicle. Once the disabledvehicle's engine is running, its alternator or generator, shouldrecharge the discharged battery, so the second battery can bedisconnected.

However, it can be quite difficult for a motorist to find anothermotorist to provide a jump start especially when the problem occurs atnight or in a remote area. Calling an automobile repair shop is asolution. But its cost is high. Emergency road servicing may not beavailable. To provide an effective, reliable emergency assistance kit toenable a motorist to deal with a dead battery is therefore an object ofthe invention.

SUMMARY OF THE INVENTION

It is therefore one object of the invention to provide a method of jumpstarting a vehicle comprising the steps of causing a control unit to seta reference voltage by choosing a point from a chart plotting voltageversus time during a starting process; determining whether the voltageacross a starting battery of the vehicle is less than the referencevoltage or not; closing a switch if the determination is positive,thereby causing an external power source to supply additional current tothe vehicle's discharged starting battery for a predetermined period oftime; adding the sufficient current and current from the dischargedstarting battery to obtain a total current; and supplying the totalcurrent to a starter motor of the vehicle so as to start the disabledvehicle.

It is another object of the invention to provide an apparatus for jumpstarting a vehicle having a starter motor and a starting batteryconnected to the starter motor, the apparatus of the inventioncomprising in combination a control unit; an external power sourceconnected in parallel to the starting battery by a switch controlled bythe control unit; wherein the control unit sets a reference voltage bychoosing a point Q from a chart plotting voltage across the startingbattery versus time for a curve representing a starting process; whereinthe control unit determines whether the voltage across the startingbattery is less than the reference voltage; wherein the switch is closedwhen the voltage across the starting battery is less than the referencevoltage as determined by the control unit; wherein the external powersource supplies a sufficient current to the starting battery, such thatthe current from the external power source and the current from thestarting battery are added to obtain a total current; and wherein thetotal current is supplied to the starter motor so as to start thevehicle.

The above and other objects, features and advantages of the inventionwill become apparent from the following detailed description taken withthe accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow chart illustrating a method for jump starting a vehicleaccording to the invention;

FIG. 2 schematically depicts an apparatus for jump starting a vehicleaccording to a first preferred embodiment of the invention;

FIG. 2A schematically depicts an apparatus for jump starting a vehicleaccording to a second preferred embodiment of the invention;

FIG. 2B schematically depicts an apparatus for jump starting a vehicleaccording to a third preferred embodiment of the invention;

FIG. 2C schematically depicts an apparatus for jump starting a vehicleaccording to a fourth preferred embodiment of the invention;

FIG. 3 schematically depicts an apparatus for jump starting a vehicleaccording to a fifth preferred embodiment of the invention;

FIG. 4 schematically depicts an apparatus for jump starting a vehicleaccording to a sixth preferred embodiment of the invention; and

FIG. 5 is a chart plotting voltage across a starting battery versus timeduring a vehicle start.

DETAILED DESCRIPTION OF THE INVENTION

As mentioned, FIG. 5 is a chart plotting voltage across a startingbattery versus time during a vehicle starting operation. A similar curveis observed in both normal and jump starts, i.e., the sharp drop-off inbattery voltage between points P2, the voltage across the battery priorto initiation of the starting operation, and P3, the minimum voltagemeasured during the starting operation, is due to the large initialcurrent drawn by operation of the starter motor. Operation of thestarter motor during cranking of the engine, is represented by sectionP4 of the curve, and P5 shows the voltage increase after the enginestarts, when the alternator or generator provides recharging current tothe battery. According to the invention, a reference voltage point Q ischosen from a point beginning at point P2 and ending at point P5 byreferring to the specifications of an automobile starting battery,manufacturer, and type. More specifically, point Q is chosen such thatif the starting battery's voltage is at least equal to Q, the batterywill likely be able to start the vehicle; if not, a jump start or otherassistance will likely be required. According to one aspect of thepresent invention, a method of providing additional power to the startermotor is provided, so that the vehicle engine can be started.

Referring to FIG. 1, a flow chart illustrating a method of jump startinga vehicle in accordance with the invention, the method comprising thefollowing steps:

Step 1: A reference voltage point Q is set by a control unit.

Step 2: It is determined whether the voltage across the starting batteryof the vehicle is less than a reference voltage point Q or not. If thedetermination is yes, the flow chart goes to next step 3. Otherwise, theflow chart returns to step 1.

Step 3: A switch 35 (discussed further below) is closed (i.e., ON)automatically, connecting an external power source to the vehicle'sdischarged battery.

Step 4: The external power source supplies additional current I₂ to thevehicle's discharged battery.

Step 5: Current I₂ and current I₁ from the vehicle's discharged batteryare added to obtain a total current I (i.e., I=1 ₁+I₂).

Step 6: The total current I is supplied to a starter motor of thevehicle so that the disabled vehicle can be started successfully.

Referring to FIG. 2, an apparatus for jump starting a vehicle accordingto a first preferred embodiment of the invention comprises the followingcomponents, as discussed in detail below.

A starting battery 10 is connected to a starter motor 20, through aconventional switched connection 33. A control unit 30 is connected tothe starting battery 10 through an analog to digital converter (A/D) 37so as to be able to measure the voltage across the battery 10. Controlunit 30 controls operation of a switch 35 so as to connect an externalpower source 50 in parallel with the starting battery 10. An input andoutput device (e.g., audible and light device, a video display, or avoltage or current value display) 31 may be provided and is connectedelectrically to the control unit 30, e.g., for display of the status ofthe external power source and associated components,

The control unit 30 can set a reference voltage Q and determine whetheran output voltage of the starting battery 10 of a disabled vehicle isless than the reference voltage Q (e.g., a point between P2 and P5 inFIG. 5) employing an analog to digital converter (A/D) 37 which usessampling to convert a continuous quantity (i.e., the voltage across thestarting battery 10) to a discrete time representation in digital form.That is, the control unit 30 can monitor the voltage across the startingbattery 10 during a normal start, effectively generating the data shownin FIG. 5, and can then select the point Q between points P2 and P5,more typically between P2 and P3. A second A/D 34 can be provided tomonitor the voltage of the external power source 50.

Preferably, the control unit 30 is an electronic control unit, asdetailed further below.

The external power source 50 is implemented as one or more cells of amobile phone, a battery of a laptop computer, one or more cells of aniPad, one or more cells of an iPhone, or one or more cells of othertypes of portable electronic device. Experiment shows that therelatively small batteries of these devices can in fact providesufficient additional current for a short time to serve as auxiliarypower sources for jump starting vehicles. Alternatively, a dedicatedexternal power source assembly (not shown) can be implemented as aplurality of series and/or parallel-connected cells.

The switch 35 is closed (ON) automatically by control unit 30,connecting the external power source 50 to the starting battery 10, whenthe output voltage of the starting battery 10 of the disabled vehicle isless than the reference voltage Q as determined by the control unit 30.When the vehicle's starting circuit 33 is then activated, the externalpower source 50 supplies high current I₂ to the vehicle's dischargedstarting battery 10. Current I₂ and current I₁ from the vehicle'sdischarged starting battery 10 are added to obtain a total current I(i.e., I=I₁+I₂). The total current I is supplied to the starter motor 20of the vehicle so that the disabled vehicle can be started successfully.

Preferably, the external power source 50 can supply high current I₂(e.g., 0.1A to 550A) of low voltage (e.g., 0.5V to 12V). Morepreferably, the high current I₂ is 1A to 50A. The typical period ofapplication of this current is between 0.001 second and 30 seconds; morepreferably, between 0.001 second and 5 seconds.

In one embodiment, the control unit, switch 35, and A/Ds 34 and 37 couldbe provided as a unit adapted to be connected between the vehicle'selectrical system (e.g., by plug-in connection to an auxiliary jack) anda portable electronic device such as a mobile phone. In this way powerfrom the battery of the mobile phone could conveniently be added to thatof the vehicle starting battery as needed to start a disabled vehicle.The control unit 30 could also be provided with a pair of spring clamps,or the like, for direct connection to the terminals of the startingbattery 10.

Referring to FIG. 2A, an apparatus for jump starting a vehicle inaccordance with a second preferred embodiment of the invention is shown.The characteristics of the second preferred embodiment are substantiallythe same as that of the first preferred embodiment of FIG. 2, except thefollowing:

A first capacitor 60 is provided in parallel to the external powersource 50 for storing electrical energy supplied therefrom. The firstcapacitor 60 can store output current from the external power source 50so as to supply high current I₂ of required voltage to the starter motor20.

As above, the switch 35 is closed (ON) automatically by control unit 30when the output voltage of the starting battery 10 of the disabledvehicle is less than the reference voltage Q as determined by thecontrol unit 30. The external power source 50 and the first capacitor 60then together supply high current I₂ to the vehicle's dischargedstarting battery 10. Current I₂ and current I₁ from the vehicle'sdischarged starting battery 10 are added to obtain a total current I(i.e., I=I₁+I₂). The high current I is supplied to the starter motor 20of the vehicle when the primary starting circuit 33 is closed, so thatthe disabled vehicle can be started successfully.

Referring to FIG. 2B, an apparatus for jump starting a vehicle inaccordance with a third preferred embodiment of the invention is shown.The characteristics of the third preferred embodiment are substantiallythe same as that of the second preferred embodiment of FIG. 2A, exceptthe following:

A direct current to direct current (DC/DC) converter 40 is provided tointerconnect the external power source 50 and the control unit 30. DC/DCconverter 40 is provided to raise the voltage from the battery of theexternal power source 50 (e.g., 6 volts) to a higher voltage (e.g., 12volts) for supply to the starter motor 20. A first capacitor 60 isprovided in parallel to the DC/DC converter 40 for storing electricalenergy supplied therefrom. The first capacitor 60 can store outputcurrent from the external power source 50 to high current I₂ of requiredvoltage.

Again, the switch 35 is closed (ON) automatically by control unit 30when the output voltage of the starting battery 10 of the disabledvehicle is less than the reference voltage Q as determined by thecontrol unit 30. The DC/DC converter 40 and the first capacitor 60 thentogether supply high current I₂ to the vehicle's discharged startingbattery 10. Current I₂ and current I₁ from the vehicle's dischargedstarting battery 10 are added to obtain a total current I (i.e.,I=I₁+I₂). The high current I is supplied to the starter motor 20 of thevehicle so that the disabled vehicle can be started successfully.

Referring to FIG. 2C, an apparatus for jump starting a vehicle inaccordance with a fourth preferred embodiment of the invention is shown.The characteristics of the fourth preferred embodiment are substantiallythe same as that of the second preferred embodiment of FIG. 2A exceptthe following:

In addition to the first capacitor 60 provided in parallel to theexternal power source 50 for storing electrical energy suppliedtherefrom, a second capacitor 61 is provided in parallel to the startingbattery 10 for storing electrical energy supplied therefrom. The firstcapacitor 60 can store output current from the external power source 50to high current I₂ of required voltage and the second capacitor 61 cansimilarly store output current from the starting battery 10 to highcurrent I₁ of required voltage.

Preferably, the capacitance of each of the first capacitor 60 and thesecond capacitor 61 is in the range of 0.01F to 1,000F depending on thecapacity of the external power source 50.

As above, the switch 35 is closed (ON) automatically by control unit 30when the output voltage of the starting battery 10 of the disabledvehicle is less than the reference voltage Q, as determined by thecontrol unit 30. The external power source 50, the first capacitor 60,and the second capacitor 61 then together supply high current I₂ to thevehicle's discharged starting battery 10. Current I₂ and current I₁ fromthe vehicle's discharged starting battery 10 are added to obtain a totalcurrent I (i.e., I=I₁+I₂). The high current I is supplied to the startermotor 20 of the vehicle so that the disabled vehicle can be startedsuccessfully.

Referring to FIG. 3, an apparatus of jump starting a vehicle inaccordance with a fifth preferred embodiment of the invention is shown.The characteristics of the fifth preferred embodiment are substantiallythe same as that of the third preferred embodiment of FIG. 2B except thefollowing:

A voltage comparator 30A is provided to replace the control unit 30 andthe two A/Ds 34 and 37. The voltage comparator 30A compares the outputvoltage of the starting battery 10 of the disabled vehicle with thereference voltage Q. The switch 35 is closed (ON) automatically when theoutput voltage of the starting battery 10 of the disabled vehicle isless than reference voltage Q as a result of the comparison made by thevoltage comparator 30A. As in the embodiment of FIG. 2B, a DC/DCconverter 40 is provided in series with the external power source 50 anda first capacitor 60 is provided in parallel to the DC/DC converter 40for storing electrical energy supplied therefrom. The first capacitor 60can store output current of the external power source 50 to provide highcurrent I₂.

Referring to FIG. 4, an apparatus for jump starting a vehicle inaccordance with a sixth preferred embodiment of the invention is shown.The characteristics of the sixth preferred embodiment are substantiallythe same as that of the third preferred embodiment of FIG. 2B except thefollowing:

The control unit 30 is replaced by a microcontroller unit (MCU) 30Bwhich is a single chip that contains a processor, RAM, ROM, clock andI/O control unit. The MCU 30B can determine whether the input voltagefrom the starting battery 10 of the disabled vehicle is less thanreference voltage point Q by cooperating with the two A/Ds 34 and 37.The switch 35 is closed (ON) automatically when the input voltage fromthe starting battery 10 of the disabled vehicle is less than thereference voltage point Q as a result of the determination made by theMCU 30B. As above, the current I₂ from the external power source 50 andthe current I₁ from the vehicle's discharged starting battery 10 areadded to obtain a total current I (i.e., I=I₁+I₂). The high current I issupplied to the starter motor 20 of the vehicle so that the disabledvehicle can be started successfully.

As above, FIG. 5 is a chart plotting voltage across the starting battery10 versus time during a starting process of an operable vehicleaccording to the first, second, third, fourth, fifth or sixth preferredembodiment of the invention. A similar Figure is shown in U.S. Pat. No.6,791,464. As indicated above, a reference voltage point Q to which thevoltage across the starting battery 10 is compared is chosen from apoint beginning at point P2 and ending at point P5 by referring to thespecifications of an automobile starting battery, manufacturer,performance and type thereof. In general, the reference voltage point Qis selected such that the method of the invention will be implementedwhen the voltage across the starting battery 10 has fallen to a pointwhere it is unlikely that the starting battery will be unable to startthe engine.

While the invention has been described in terms of preferredembodiments, those skilled in the art will recognize that the inventioncan be practiced with modifications within the spirit and scope of theappended claims.

What is claimed is:
 1. A method of jump starting a vehicle comprisingthe steps of: setting a reference voltage point Q by choosing the pointQ from a range of voltages across a starting battery of the vehiclemeasured during the process of starting the vehicle; determining whetherthe voltage across the starting battery of the vehicle is less than thereference voltage Q; if the determination is positive, causing anexternal power source to supply high current (I₂) to the startingbattery, thereby adding the high current (I₂) to current (I₁) from thestarting battery to obtain a total current (I); and supplying the totalcurrent (I) to a starter motor of the vehicle so as to successfullystart the vehicle.
 2. The method of claim 1, wherein the period of timeof supplying current by the external power source in jump starting thevehicle is between about 0.001 second and 30 seconds.
 3. The method ofclaim 2, wherein the period of time of supplying current by the externalpower source in jump starting the vehicle is between about 0.001 secondand 5 seconds.
 4. The method of claim 1, wherein the high current (I₂)supplied by the external power source is between about 0.1A and 550A. 5.The method of claim 1, wherein current supplied by the external powersource is stored in a capacitor prior to supply to the starter motor ofthe vehicle.
 6. The method of claim 1, wherein the voltage of thecurrent supplied by the external power source is increased to a highervoltage in a DC to DC converter prior to supply to the starter motor ofthe vehicle.
 7. The method of claim 1, wherein said step of setting areference voltage point Q by choosing the point Q from a range ofvoltages across a starting battery of the vehicle measured during theprocess of starting the vehicle is performed by detecting specificpoints in the variation of range of voltages measured in a startingoperation, these points including P2, the voltage prior to initiatingthe starting operation; P3, the minimum voltage reached at theinitiation of the starting operation; P4, the voltage measured duringcranking of the engine; and P5, the voltage measured after the enginestarts, and choosing reference voltage point Q from between the voltagemeasured at P2 and the voltage measured at P5.
 8. The method of claim 7,wherein reference voltage point Q is chosen from between the voltagemeasured at P2 and the voltage measured at P3.
 9. An apparatus for jumpstarting a vehicle comprising a starter motor and a starting batteryconnected to the starter motor, said apparatus comprising: a controlunit connected to the starting battery; an external power source; aswitch controlled by the control unit to selectively connect theexternal power source to the starting battery; wherein the control unitcompares the voltage across the starting battery to a reference voltageQ, and closes the switch when the voltage across the starting battery isless than the reference voltage Q such that the external power sourcesupplies a high current (I₂) to the starting battery, such that the highcurrent (I₂) is added to current (I₁) from the starting battery toobtain a total current (I); and the total current (I) is supplied to thestarter motor so as to start the vehicle.
 10. The apparatus of claim 9,wherein the reference voltage Q is set by the control unit by referringto the specifications of an automobile starting battery, manufacturer,and type by choosing a point along a curve of voltage across thestarting battery versus time as measured during the starting of avehicle.
 11. The apparatus of claim 9, further comprising a firstcapacitor connecting to the external power source for storingelectricity from the external power source and supplying high current(I₂) when the switch is closed.
 12. The apparatus of claim 11, furthercomprising a second capacitor connected to the starting battery of thevehicle for storing electricity from the starting battery of the vehicleand supplying high current (I₂) to the starter motor when the vehicle'sstarting circuit is activated.
 13. The apparatus of claim 9, furthercomprising a direct current to direct current (DC/DC) converterconnected to the external power source so that the voltage of thecurrent (I₂) from the external power source can be increased to a valuesuitable for powering the starter motor.
 14. The apparatus of claim 13,further comprising a first capacitor connected to the DC/DC converter sothat the voltage of the current (I₂) from the external power source canbe increased to a value suitable for powering the starter motor by theDC/DC converter and stored in the first capacitor for supply to thestarter motor.
 15. The apparatus of claim 9, wherein the external powersource is implemented as a plurality of cells connected in series,parallel, or series and parallel.
 16. The apparatus of claim 9, whereinthe control unit further comprises an input and output device forproviding an indication of the status of the device.
 17. The apparatusof claim 9, wherein the control unit is a microcontroller unit.
 18. Theapparatus of claim 9, wherein the control unit is a voltage comparator.19. The apparatus of claim 9, wherein the external power source is oneor more cells of a mobile phone, a battery of a laptop computer, or oneor more cells of a portable electronic device.
 20. The apparatus ofclaim 9, wherein the high current (I₂) is supplied by the external powersource for between about 0.001 second and 30 seconds.
 21. The apparatusof claim 9, wherein the high current (I₂) is supplied by the externalpower source for between about 0.05 seconds and 5 seconds.
 22. Theapparatus of claim 9, wherein the high current (I₂) supplied by theexternal power source is between about 0.1A and 550A.
 23. The apparatusof claim 11, wherein the first capacitor has a capacitance in the rangeof 0.01 F to 1,000F.
 24. The apparatus of claim 9, wherein saidreference voltage point Q is chosen from a range of voltages across astarting battery of the vehicle measured during the process of startingthe vehicle, wherein specific points in the variation of range ofvoltages measured in a starting operation are detected, these pointsincluding P2, the voltage prior to initiating the starting operation;P3, the minimum voltage reached at the initiation of the startingoperation; P4, the voltage measured during cranking of the engine; andP5, the voltage measured after the engine starts, and wherein referencevoltage point Q is chosen from between the voltage measured at P2 andthe voltage measured at P5.
 25. The apparatus of claim 24, whereinreference voltage point Q is chosen from between the voltage measured atP2 and the voltage measured at P3.